Ultrashort Pulse Amplification In The Process Of Pulse Width And Spectral Characteristics

Recently, the ultrashort pulse laser has developed into a prosperous front scientific research field in the world. The research of the nonlinear effects and its influences to the laser pulse duration and spectrum bandwidth, and that of the effective pulse duration compressing by corresponding technique have practical significance in the processes of the transmission and amplification of the ultrashort pulse laser.In this article, some works have been done such as the theoretical analysis and experimental research for the influences to the pulse duration and bandwidth due to the effects of the self-phase modulation(SPM) and the group velocity dispertion(GVD) in the window material of the amplifier.For the system of the desk ultrashot pulse laser in our laboratory, this article compresses the pulse duration with the prisms pair, and it also researches the influences of the experimental conditions to the pulse duration and spectrum bandwidth. In the amplifying, the experiments' results show that the existence of the SPM in the window material accelerates the speed of the widening of the pulse duration compared by the GVD only, and that the SPM in the window material and the gain narrowing of the amplifying medium make the output pulse bandwidth vary very little, and also that the compressing of the pulse duration by introducing the linear negative chirp into the pulse to compensate the positive chirp of the pulse is practical. These results establish the base of amplifying the pulse laser in the desk system and further in the excimer laser amplifier pumped by the electron beams.